Metal alloys for medical devices

• US 7,648,591 B2
• Filed: 11/17/2008
• Issued: 01/19/2010
• Est. Priority Date: 03/03/2005
• Status: Active Grant

• Current Assignee: Mirus LLC
• Original Assignee: Icon Medical Corp. (ICON Interventional Systems, Inc.)
• Inventors: Furst, Joseph G., Patel, Udayan, Buckman, Raymond W. Jr.
• Primary Examiner(s): Wyszomierski; George
• Assistant Examiner(s): Shevin; Mark L
• Application Number:
  US12/272,317
• Publication Number:
  US 20090068249A1
• Time in Patent Office: 428 Days
• Field of Search: 148/423, 420/429, 420/433
• US Class Current: 148/423
• CPC Class Codes: A61F 2/91 made from perforated sheet material or tubes, e.g. perforated by laser cuts or etched holes
• CPC Class Codes: A61P 35/00 Antineoplastic agents
• CPC Class Codes: A61P 37/06 Immunosuppressants, e.g. drugs for graft rejection
• CPC Class Codes: A61P 43/00 Drugs for specific purposes, not provided for in groups A61P1/00-A61P41/00
• CPC Class Codes: A61P 7/02 Antithrombotic agents; Anticoagulants; Platelet aggregation inhibitors
• CPC Class Codes: A61P 9/00 Drugs for disorders of the cardiovascular system
• CPC Class Codes: B22F 1/09 Mixtures of metallic powders
• CPC Class Codes: B22F 2003/248 Thermal after-treatment
• CPC Class Codes: B22F 2201/01 Reducing atmosphere
• CPC Class Codes: B22F 2201/10 Inert gases
• CPC Class Codes: B22F 2201/20 Use of vacuum
• CPC Class Codes: B22F 2998/00 Supplementary information concerning processes or compositions relating to powder metallurgy
• CPC Class Codes: B22F 2998/10 Processes characterised by the sequence of their steps
• CPC Class Codes: B22F 2999/00 Aspects linked to processes or compositions used in powder metallurgy
• CPC Class Codes: B22F 3/04 by applying fluid pressure , e.g. by cold isostatic pressing [CIP]
• CPC Class Codes: B22F 3/10 Sintering only
• CPC Class Codes: B22F 3/16 in successive or repeated steps
• CPC Class Codes: B22F 3/20 by extruding
• CPC Class Codes: B22F 3/24 After-treatment of workpieces or articles B22F3/1146 takes precedence
• CPC Class Codes: B22F 5/10 of articles with cavities or holes, not otherwise provided for in the preceding subgroups
• CPC Class Codes: B22F 5/106 : Tube or ring forms
• CPC Class Codes: C22C 27/00 : Alloys based on rhenium or a refractory metal not mentioned in groups C22C14/00 or C22C16/00
• CPC Class Codes: C22C 27/04 : Alloys based on tungsten or molybdenum
• CPC Class Codes: C22C 30/00 : Alloys containing less than 50% by weight of each constituent
• CPC Class Codes: C22F 1/18 : High-melting or refractory metals or alloys based thereon
• CPC Class Codes: Y10S 606/907 : Composed of particular material or coated

Abstract

A medical device that is at least partially formed of a novel metal alloy, which novel metal alloy improves the physical properties of the medical device.

Claims

1. A medical device at least partially formed of a metal alloy which improves the strength and radiopacity of the medical device, said metal alloy including at least about 95 weight percent of a solid solution of rhenium and molybdenum, said metal alloy including 40-55 weight percent rhenium and 45-60 weight percent molybdenum, said metal alloy including carbon, nitrogen and oxygen, said metal alloy having a nitrogen content of less than about 20 ppm, a carbon content of less than about 150 ppm, and an oxygen content of less than about 75 ppm, said metal alloy having a carbon to oxygen atomic ratio of at least about 1:

1, said metal alloy having a carbon to oxygen atomic ratio of less than about 50;

1, at least one region of said medical device including biological agent, polymer, micro-structure, or combinations thereof.

2. The medical device as defined in claim 1, wherein said metal alloy has an average yield strength of at least about 95 ksi and an average ultimate tensile strength of at least about 95 ksi, said metal alloy having an average grain size of over 5 ASTM, and said metal alloy having an average tensile elongation of at least about 25%.

3. The medical device as defined in claims 1 or 2, wherein said medical device is a stent, graft, valve, screw, nail, rod, PFO device, prosthetic device, sheath, guide wire, balloon catheter, hypotube, catheter, electrophysiology catheter, staple or cutting device.

4. The medical device as defined in claim 1, wherein said metal alloy includes over 99 weight percent of a solid solution.

5. The medical device as defined in claim 4, wherein said metal alloy includes at least about 99.95 weight percent of a solution.

6. The medical device as defined in claim 1, wherein said metal alloy has an average density of at least 10 gm/cc.

7. The medical device as defined in claim 5, wherein said metal alloy has an average density of at least 10 gm/cc.

8. The medical device as defined in claim 1, wherein said metal alloy includes about 46-49 weight percent rhenium and about 51-54 weight percent molybdenum.

9. The medical device as defined in claim 7, wherein said metal alloy includes about 46-49 weight percent rhenium and about 51-54 weight percent molybdenum.

10. The medical device as defined in claim 1, wherein said metal alloy includes about 40-50 weight percent rhenium and about 50-60 weight percent molybdenum.

11. The medical device as defined in claim 7, wherein said metal alloy includes about 40-50 weight percent rhenium and about 50-60 weight percent molybdenum.

12. The medical device as defined in claim 1, wherein said carbon content of said metal alloy is less than about 100 ppm and said oxygen content of said metal alloy is less than about 50 ppm, and a carbon to oxygen atomic ratio of at least about 2:

1.

13. The medical device as defined in claim 9 or 11, wherein said carbon content of said metal alloy is less than about 100 ppm and said oxygen content of said metal alloy is less than about 50 ppm, and a carbon to oxygen atomic ratio of at least about 2:

1.

14. The medical device as defined in claim 12, wherein said carbon content of said metal alloy is less than about 50 ppm and said oxygen content of said metal alloy is less than about 10 ppm.

15. The medical device as defined in claim 13, wherein said carbon content of said metal alloy is less than about 50 ppm and said oxygen content of said metal alloy is less than about 10 ppm.

16. The medical device as defined in claim 1, wherein said atomic ratio of carbon to oxygen in said metal alloy is up to about 20:

1.

17. The medical device as defined in claim 15, wherein said atomic ratio of carbon to oxygen in said metal alloy is up to about 20:

1.

18. The medical device as defined in claim 1, wherein said nitrogen content of said metal alloy is less than about 10 ppm.

19. The medical device as defined in claim 17, wherein said nitrogen content of said metal alloy is less than about 10 ppm.

20. The medical device as defined in claim 1, wherein said metal alloy has an average grain size of about 5-10 ASTM.

21. The medical device as defined in claim 19, wherein said metal alloy has an average grain size of about 5-10 ASTM.

22. The medical device as defined in claim 1, wherein said metal alloy comprises by weight percent:

23. The medical device as defined in claim 21, wherein said metal alloy comprises by weight percent:

24. The medical device as defined in claim 1, wherein said metal alloy comprises by weight percent:

25. The medical device as defined in claim 21, wherein said metal alloy comprises by weight percent:

26. The medical device as defined in claim 1, wherein said metal alloy comprises by weight percent:

27. The medical device as defined in claim 21, wherein said metal alloy comprises by weight percent:

28. The medical device as defined in claim 1, wherein said metal alloy including an additional metal, said additional metal constituting less than about 10 weight percent of said metal alloy, said additional metal including one or more metals selected from the group consisting of titanium, yttrium, and zirconium.

29. The medical device as defined in claim 21, wherein said metal alloy including an additional metal, said additional metal constituting less than about 10 weight percent of said metal alloy, said additional metal including one or more metals selected from the group consisting of titanium, yttrium, and zirconium.

30. The medical device as defined in claim 28, wherein said titanium content is less than about 1 weight percent of said metal alloy, said yttrium content is less than about 0.3 weight percent of said metal alloy, and said zirconium content is less than about 0.5 weight percent of said metal alloy.

31. The medical device as defined in claim 29, wherein said titanium content is less than about 1 weight percent of said metal alloy, said yttrium content is less than about 0.3 weight percent of said metal alloy, and said zirconium content is less than about 0.5 weight percent of said metal alloy.

32. The medical device as defined in claim 28, wherein said metal alloy includes titanium and zirconium, said titanium and zirconium having a weight ratio of about 1-10:

1.

33. The medical device as defined in claim 31, wherein said metal alloy includes titanium and zirconium, said titanium and zirconium having a weight ratio of about 1-10:

1.

34. The medical device as defined in claim 1, wherein said medical device includes polymer and biological agent, said polymer at least partially coating said biological agent, encapsulating said biological agent, and combinations thereof.

35. The medical device as defined in claim 21, wherein said medical device includes polymer and a biological agent, said polymer at least partially coating said biological agent, encapsulating said biological agent, and combinations thereof.

36. The medical device as defined in claim 1, wherein said medical device includes said polymer, said polymer includes one or more compounds selected from the group consisting of parylene, a parylene derivative, chitosan, a chitosan derivative, PLGA, a PLGA derivative, PLA, a PLA derivative, PEVA, a PEVA derivative, PBMA, a PBMA derivative, POE, a POE derivative, PGA, a PGA derivative, PLLA, a PLLA derivative, PAA, a PAA derivative, PEG, and a PEG derivative.

37. The medical device as defined in claim 1, wherein medical device includes biological agent, said biological agent includes one or more compounds selected from the group consisting of trapidil, trapidil derivatives, taxol, taxol derivatives, cytochalasin, cytochalasin derivatives, paclitaxel, paclitaxel derivatives, rapamycin, rapamycin derivatives, GM-CSF, and GM-CSF derivatives.

38. The medical device as defined in claim 1, wherein said medical device includes said micro-structure on an outer surface of said medical device.

39. The medical device as defined in claim 38, wherein said at least one micro-structure is at least partially formed of, includes, or combinations thereof, a material comprising a said polymer, said biological agent, and combinations thereof.

40. A stent that is formed of at least about 80 weight percent of a metal alloy which improves the strength and ductility of the stent, said metal alloy including at least about 99.9 weight percent of a solid solution of rhenium and molybdenum, said metal alloy including carbon and oxygen and having a carbon to oxygen atomic ratio of at least about 1:

1 and less than about 50;

1, said metal alloy having an average yield strength of about 98-122 ksi and an average ultimate tensile strength of about 100-150 ksi, said metal alloy having an average grain size of about 6-9 ASTM, said metal alloy having an average tensile elongation of about 25-35%, at least one region of said medical device including biological agent, polymer, micro-structure, or combinations thereof, said medical device including by weight percent;

41. The stent as defined in claim 40, wherein said metal alloy comprises by weight percent:

42. The stent as defined in claim 40, wherein said metal alloy including an additional metal, said additional metal constituting less than about 10 weight percent of said metal alloy, said additional metal including one or more metals selected from the group consisting of titanium, yttrium, and zirconium, said titanium content is less than about 1 weight percent of said metal alloy, said yttrium content is less than about 0.3 weight percent of said metal alloy, and said zirconium content is less than about 0.5 weight percent of said metal alloy.

43. The stent as defined in claim 41, wherein said metal alloy including an additional metal, said additional metal constituting less than about 10 weight percent of said metal alloy, said additional metal including one or more metals selected from the group consisting of titanium, yttrium, and zirconium, said titanium content is less than about 1 weight percent of said metal alloy, said yttrium content is less than about 0.3 weight percent of said metal alloy, and said zirconium content is less than about 0.5 weight percent of said metal alloy.

44. A medical device at least partially formed of a metal alloy which improves the strength and radiopacity of the medical device, said metal alloy including at least about 95 weight percent of a solid solution of rhenium and molybdenum, said metal alloy including at least 40 weight percent rhenium and at least 40 weight percent molybdenum, said metal alloy including carbon, nitrogen and oxygen, said metal alloy having a nitrogen content of less than about 30 ppm, a carbon content of up to 200 ppm, and an oxygen content of up to 100 ppm, said metal alloy having a carbon to oxygen atomic ratio of at least about 1:

1, said metal alloy having a carbon to oxygen atomic ratio of less than about 50;

1, said metal alloy having an average yield strength of at least about 70 ksi and an average ultimate tensile strength of about 80-150 ksi, said metal alloy having an average grain size of over 5 ASTM, said metal alloy having an average tensile elongation of at least about 25%, at least one region of said medical device including biological agent, polymer, micro-structure, or combinations thereof.